Van

Now, gang, here's a long post showing what I did to split the case. Lots of pictures and all, so if you have dial-up, now would be a good time to go get a cup of coffee or run an errand.


So, now that the heads, pistons and cylinders are off, it's now time to "split the case" and finish the disassembly.

On the bottom of the engine, we need to remove the oil sump cover, the inspection cover and the oil pump (which is on the front).




Here the sump cover is off:




What's behind it is a strainer screen (which has trapped some little piece of case sealant from the previous rebuild):




Here's the case with the strainer out:




And the case with the inspection cover off:



The oil pump is mounted on the front of the engine:




Once it's removed, you can see how it's driven by the camshaft - the pump shaft has a tab that goes into the slot on the cam:




Now its time to make sure all the perimeter bolts are removed (if I recall, there are 20):




And then take the nuts off of the 6 large "case through bolts". These through bolts are what provide the clamping force for supporting the crank (they're located at the crank bearing locations) - the perimeter bolts are primarily to seal the case so the oil doesn't leak out.





There are now no fasteners holding the case together - just friction (from close tolerance fits) and the sealant that was used on the case mating surfaces. Because I'm using a conventional engine stand, I have to take the engine off (the stand has bolts through both case halves). They do make a special VW engine stand that just bolts to one case half, which lets you remove the other half - but I'd have to build a few more of these to justify purchasing one!

With gentle prying and tapping, I was able to persuade the case halves to come apart! Here's what it looks like opened up:




Note how those case through bolts line up with the main crank bearings. Here you can see how the camshaft is driven - a simple gear drive from the crank (at a 2:1 ratio - for every 2 turns of the crank (4 strokes) the cam makes 1 revolution). That other spiral gear drives the distributor.




The cam just lifts out, leaving its bearings in place:




All of the bearings (cam and crank) have holes and corresponding oil galleys in the case. The oil pump provides oil pressure to force the oil out of these holes to continuously lubricate the rotating components. The crankshaft's main journals have holes, which connect to passage ways to the rod journals - this allows the oil to pump from the case, through the main bearings, and to the rod bearings, to keep them lubricated. The oil then drips back down to the sump and is recirculated by the oil pump.

By grabbing the two rods, I lifted the crankshaft assembly right out:




And set it on the floor:




Now it's time to turn our attention back to the other case half. This one has the oil pickup and a baffle to prevent the oil from sloshing around too much:




To remove the baffle, the one bolt going through the oil pickup needs to be removed:




The baffle now lifts right out:




And now the oil pickup can be lifted out:




Here are the two case halves ready to be cleaned up!

Slantnose!

Good stuff!
Feel like I was there...

Van

I'm going to use a new crankshaft and new connecting rods for the rebuild, so I don't need to take the rods off of the old crank, but I'm curious about what the bearings look like.

First step is to remove the nuts:




Then the rods just pull away from the "caps":




All four are off and their bearings lined up:




Here's a close-up of the bearings to see the wear. Compared to the main bearings, these show a lot more wear, but I don't think it's serious or anything to be concerned about.




Next I pull the fan hub with a puller (this will be reused on the new crank):




And the distributor and cam drive gears will also have to be moved over to the new crank.




I now declare the engine officially apart! The flywheel is off at the machine shop getting resurfaced, and the cylinders are getting cleaned up to be reused with the new pistons.

After the crank, rods and pistons show up, those will be sent out with the flywheel and blower fan to be balanced.

Then it'll be time to "assemble in reverse order" - and it'll be done!

Mike S.

Hi Van,

Looks like you're up to no good! Great photos and explanations. Thanks. I learned a lot!

What the current engine torque and power and what do you expect to get with this rebuild?

Mike

P.S. Guess who's the instructor sitting next to me in my avatar???? Hard to see, but "he's" looking way ahead (past the corner) and setting the right example for me to follow!

FlatSix911

Great write up and photos ... keep them coming

Jay Gratton

Wonderful thread! I wish everyone can see it from the other threads.

Van

Thanks for the comments!

Not a whole lot of major stuff going on this weekend - mostly cleaning parts. But I should have some more pictures by the end of tomorrow.

Hey Mike, I expect much more power, of course, but even better than that, I expect a lot of torque and a broad power band.

I've never thad that car on a dyno, so I don't know how much power it was making... The original 1.8 with fuel injection made about 75 HP. Mine was over-bored to about 1.97 and had carbs - but, due to the compression ratio and cam, the carbs probably werent adding much power. So maybe I was making 85 HP - maybe 90, if you're really generous?

Anyhow, here's the HP/torque curve on another Jake Raby engine:



The engine I'm doing has the same specs, however, mine will have heads that flow a little more and feature a slightly different combustion chamber. If I make 150 with a torque curve like that, I'll be quite happy!

Mike S.

Van,

That's quite the improvement and should move the 2100 lbm car around pretty well. Are you doing anything special in the gearing department? And will it be getting some track time?

Mike

Rotten Robby

My Raby 2270 kit was probably the best money I have ever spent on a car period. Everything you need to build the engine is in there. In fact, it is so complete, I thought he had accidently left out the six pack of beer.

My engine is around 175HP and the torque comes on pretty much off idle and stays with you until redline. I have said it before on other sites and I will repeat it now here, this is the engine VW-Porsche should have put in the car. If they had, you might be able to drive an '85 Boxster today... Or an '80 914...

The heads are half the kit price. Dig deep. If you try to mimic a Jake kit, you will fail. The heads are just one important part. The cam is crucial.

Van

Thanks for the encouraging words, Robby. I was going to just try and mimic a Jake kit - but after getting a DPR 78mm crank for a good price and talking with Jake, I'm getting everything else I need from him (and he'll also do my balancing).

Mike, I don't plan on taking the 914 to the track, though I hope to autocross it a bit (I used to auto-x the car a lot, many years ago). For what it's worth, the 944 and 996 are safer (harnesses, race seats, etc) and more easily replaced if something unfortunate happened.

Slantnose!

What class will it run in now?

Van

Here's some eye candy! The new connecting rods have shown up. They are quite pretty, and a bit lighter, too. The new ones are 20 oz, vs 27 oz.

Van

I don't know what auto-x class it would be in. I used to do a lot of autocross with a local club that put me in "import"...

I just wanna go have some fun!

Slantnose!

Oh...
I was wondering about which SCCA-type class it would wind up in.
Mine is F/P, but suppose you'd be in E/M or maybe a SM something.
Fun for sure.

Van

Updates on my engine progress!!

It looks like the last thing I did was to remove the fan hub...

Now it's time to remove the gears from the old crankshaft. There is a spring clip retaining ring, the brass (or perhaps bronze) distributor drive gear, a spacer, the camshaft drive gear and the two semi-circular keys.

First I heated up the distributor drive gear with my torch, and once it got hot enough, it just lifted right off the crank.





Then the spacer ring came off, too. To get the large gear off, I had to resort to the hydraulic press... but I didn't have any good way to support the gear. So I welded up a little fixture with some channel stock I had laying around (note the cross brace to make sure my pieces of channel stock wouldn't scoot away to the side when I applied pressure).





It worked like a charm, and in moments, the gear was free!





The woodruff keys are semi-circular, which means you can tap on one end with a hammer (and a punch, or suitable screwdriver...) and get them to rotate in their pockets, then pull them out. Now I await the new crank!